1. What is a Passenger Service System?

A passenger service system (PSS) is at the core of an airline’s IT infrastructure. This is the system responsible for managing customer interactions with airlines, from booking a ticket to boarding the flight.

It consists of various components offered by different software providers, most commonly Amadeus, Sabre and Navitaire. PSSs also usually interact with other airline IT systems, and are critical for smooth airline operations. Problems with PSSs have paralyzed airlines and cost them hundreds of millions in lost revenue. in 2012, the United-Continental PSS merger caused chaos for everyone involved.

The PSS is often called several different names, such as the "reservation system", the vendor name (for example Navitaire or Sabre), or incorrectly as the GDS (global distribution system), because GDS providers often produce PSSs. However, the actual PSS will usually have its own product name, such as Navitaire's "New Skies" or Sabre's "Sabresonic".

The image below shows the Navitaire Core PSS and integrations. It shows the different products bundled within the New Skies PSS, the integrations with external interfaces such as ATPCO (fare information), OAG (scheduling information) and additional Navitaire products that can integrate with the PSS. With Navitaire, the DCS is bundled separately from the core PSS.

4. How a PSS Handles Direct Bookings

A customer visits the airline's website to search for and book flights with the IBE.

The IBE queries the inventory system to check flight availability and pricing.

The customer books a ticket, which places the reservation in the CRS.

Around 24 hours before departure, the CRS pushes passenger information to the DCS to begin the check in, baggage and boarding processes. The DCS will usually store this information for 12-24 hours after the flight is completed.

5. How Does a PSS Connect with Other Airline IT Infrastructure?

The core PSS is usually able to connect to other systems including revenue management, revenue accounting, GDS and interline booking. These systems communicate through an IATA standard called ATA-IATA Reservation Interline Messaging Procedures (AIRIMP), which PSS providers are required to comply with. This allows easy compatibility with third party systems.

The connection with revenue management systems is shown below. The reservation system sends information about customer purchase history to the RM system, which is combined with product information and pricing information into a data collection layer. This is then optimized by revenue managers, who then send allocation decisions and overbooking allowances back into the inventory system.

PSSs are also tightly integrated with GDSs, as this is often a large distribution segment for airlines. It's connected through several points: the inventory system, the reservation system and the settlement mechanism.

The inventory system is used through the construction of an offer and the reservation system is used once a ticket is purchased. The settlement mechanism is through the IATA BSP, which allows for a single payment to be processed and sent to the airlines.

The PSS and GDS communicate through Type A messaging format (EDIFACT) and Type B messaging, or through an XML-based connection.

6. Examples of PSSs

The most common PSSs by market share are Navitaire's New Skies, Amadeus's Altea and Sabre's Sabresonic CSS. PSSs from Radixx and Navitaire are mainly for low-cost carriers, while those from Sabre, Amadeus and Mercator are for full-service carriers. In the Chinese market, airlines almost exclusively use the PSS from the state-owned Travelsky.

Some airlines have developed PSSs internally, including Aer Lingus (Astral), Iberia (RESIBER) and Alitalia (ARCO). However, this is costly and often less efficient.

At Yieldr, we looked at the most used passenger service systems across the world, based on the total available seat kilometers per airline (ASK). You can see the results in our infographic.